/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/CollisionConvexMesh.h
Find edge pairs that are colinear and remove the unnecessary vertex to make a single edge. If we are left with an invalid face (2 verts or less), remove it. NOTE: a vertex in the middle of two colinear edges on one face may still be required by some other face, although technically those faces could (and should) have been merged.
static void MergeColinearEdges ( [TArray](API\Runtime\Core\Containers\TArray)< [FPlaneType](API\Runtime\Chaos\Chaos\TPlaneConcrete) > & InOutPlanes, [TArray](API\Runtime\Core\Containers\TArray)< [TArray](API\Runtime\Core\Containers\TArray)< int32 >> & InOutFaceVertexIndices, [TArray](API\Runtime\Core\Containers\TArray)< [FVec3Type](API\Runtime\ChaosCore\Chaos\TVector_T_3) > & InOutVertices, FRealType AngleToleranceRad )